package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import io.lettuce.core.RedisCommandExecutionException;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Autowired
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisidworker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService executor = Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init() {
        executor.submit(new VoucherOrderHandler());
    }
private class VoucherOrderHandler implements Runnable{

        String queueName = "stream.orders";
    @Override
    public void run() {
            while (true) {
                try {
                    List<MapRecord<String, Object, Object>> read = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1")
                            , StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2))
                            , StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    if (read == null || read.isEmpty()) {
                        //没有消息，继续下一次循环
                        continue;
                    }
                    //解析消息中的数据
                    MapRecord<String, Object, Object> record = read.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    handleVoucherOrder(voucherOrder);
                    //确认消息
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1", record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }

    private void handlePendingList() {
        while (true) {
            try {
                List<MapRecord<String, Object, Object>> read = stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1", "c1")
                        , StreamReadOptions.empty().count(1)
                        , StreamOffset.create(queueName, ReadOffset.from("0"))
                );
                if (read == null || read.isEmpty()) {
                    break;
                }
                //解析消息中的数据
                MapRecord<String, Object, Object> record = read.get(0);
                Map<Object, Object> values = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                handleVoucherOrder(voucherOrder);
                stringRedisTemplate.opsForStream().acknowledge(queueName,"g1", record.getId());
            }
            catch (Exception e) {
                log.error("处理pending-list订单异常", e);
                try {
                    Thread.sleep(20);
                }
                catch (InterruptedException interruptedException) {
                    interruptedException.printStackTrace();
                }
            }
        }
    }
}
//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
//    private class VoucherOrderHandler implements Runnable{
//        @Override
//        public void run() {
//            while (true) {
//                try {
//                    //获取队列中的订单信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //获取用户，查询用户是否存在
//                    Long userId = voucherOrder.getUserId();
//                    if (userId.equals(userId)) {
//                        //创建订单
//                        handleVoucherOrder(voucherOrder);
//                    }
//                } catch (Exception e) {
//                    log.error("处理订单异常", e);
//                }
//            }
//        }
//    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();
        if (!isLock) {
            log.error("不允许重复下单");
            return;
        }
        try {
            proxy.CreateVoucherOrder(voucherOrder);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        }
        finally {
            lock.unlock();
        }
    }
private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
            Long userId = UserHolder.getUser().getId();
            long orderId = redisidworker.nextId("order");
            //执行lua脚本
            Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(),
                    voucherId.toString(), userId.toString(), String.valueOf(orderId));
            int r = result.intValue();
            if (r != 0){
                return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
            }
            proxy = (IVoucherOrderService) AopContext.currentProxy();
            return Result.ok(orderId);
    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//            Long userId = UserHolder.getUser().getId();
//            //执行lua脚本
//            Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(),
//                    voucherId.toString(), userId.toString());
//            int r = result.intValue();
//            if (r != 0){
//                return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
//            }
//            VoucherOrder order = new VoucherOrder();
//            long orderId = redisidworker.nextId("order");
//            order.setUserId(userId);
//            order.setVoucherId(voucherId);
//            order.setId(orderId);
//            orderTasks.add(order);
//            proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return Result.ok(orderId);
//    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        // TODO: 2022/5/18 秒杀券实现
//        SeckillVoucher seckill = seckillVoucherService.getById(voucherId);
//        if (seckill.getBeginTime().isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀尚未开始");
//        }
//        if (seckill.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束");
//        }
//        if (seckill.getStock() < 1) {
//            return Result.fail("库存不足");
//        }
//        Long userId = UserHolder.getUser().getId();
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            return Result.fail("请勿重复下单");
//        }
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.CreateVoucherOrder(voucherId);
//        } catch (IllegalStateException e) {
//            throw new RuntimeException(e);
//        }
//        finally {
//            lock.unlock();
//        }
//    }
    @Transactional
    public void CreateVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();

        if (this.query().eq("user_id", userId).eq("voucher_id", voucherOrder).count()>0){
            log.error("用户已经购买过一次");
            return ;
        }
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0)
                .update();
        if (!success) {
            log.error("库存不足");
            return ;
        }
        save(voucherOrder);
    }
}
